He is a far cry from the maniacal character he plays on cult TV comedy series Community - that of Spanish teacher-turned-homeless man Ben Chang, who thinks up ways to torment people around him to achieve his aims.

Over the telephone from his home in Los Angeles, the 42-year-old tells Life! that others are constantly taken aback by how different he is in real life to his character.

'People are often surprised by how strict I actually am in my life but I think that's just the way I was brought up,' says the Korean-American.

Jeong, who was a medical doctor moonlighting in comedy clubs before he switched to acting full-time in 2007, adds: 'I guess it's also because you have to have some sort of discipline going through a good college and then medical school, so that's the way I am. And people are always surprised to see all of that.'

Only at one point during the 15-minute interview session did he let slip a peek of his kooky character - when he was in the middle of dishing out parenting advice.

The father of twin four-year-old girls starts off seriously enough, saying: 'My kids are so wonderfully well-behaved that it's really rare for me to give them time-outs or anything like that. But I guess I have a very 'zen' philosophy when it comes to parenting.

'Let's say you catch your child stealing a glass of milk and then breaking the glass. What do you do? Do you break (sic) the kid and send them to their room while you clean up the mess? No. You have the kid clean up. I'm looking at more constructive ways of parenting.'

As he goes on gravely about 'negative versus positive reinforcement', Jeong suddenly pauses.

He then bursts into wild laughter, complete with heaving and puffing, and says: 'This is such a funny situation. Can you ever imagine Senor Chang getting all 'zen-like' and giving such serious parenting advice? This must be so funny for you right now.'

Other than the role of Ben Chang, Jeong is also famous for playing the equally insane character of flamboyant gangster Leslie Chow in The Hangover movies (2009 and 2011). The character, who is of Chinese heritage, speaks pidgin English and tends to screech and laugh hysterically for no reason.

Though lauded by fans as one of the film series' main scene-stealers, the role has been criticised by others as perpetuating the stereotype of Asians as weird.

Jeong points out, however, that comedy means always parodying someone or something else. 'You're always making fun of an archetype, whatever that may be. Trust me, I've done a lot of roles without accents that were far more offensive.

'For me, it's just important that you find the aspect or angle of playing a character where the comedy becomes meta-level almost.'

The fact that Asian-American actors are being offered more diverse roles nowadays is also something he does not take for granted.

Referring to Korean-American actors Daniel Dae Kim and John Cho, he says: 'Daniel and John are great friends of mine and we're all different people, playing different personalities. It's great that people are seeing more diversity among Asian actors on TV and film.

'There's always a tapestry of personalities and approaches, which I think is being reflected more now. It is very exciting to watch and be a part of all that.'

These days, Jeong is simply 'grateful' to be able to do what he loves: acting.

'Ten years ago, I was a full-time doctor, so I could never have predicted any of this. I still can't believe any of this. So honestly, it still boggles my mind that I'm a working actor now.

'And to be part of a show like Community, which is an amazing show that I'm genuinely a fan of myself, it's just all a dream come true - and more.'